Radial microstructure and optical properties of porous silicon layer

The paper investigated the radial refractive index and optical and actual thickness of the PS structures fabricated by means of the reflectance spectroscopy, photoluminescence spectroscopy and scanning electron microscopy (SEM). The relationship between the radial refractive index n and optical thickness (nd) of PS sample and the distance away from the etched centre along the radial direction has been detailedly analyzed. With the distance far away from the etched centre, the radial refractive index n increases, indicating that the porosity becomes smaller. Meanwhile, the reflectance spectra exhibit the less intense interference oscillations which mean the uniformity and interface smoothness of PS layers become worse.